Nonscalding water heater



May ll 1926.

F. J. POSTEL NoNscALDING WATER HEATER Filed July 5o 192:5

Patented llla-y "1 1, 1926.-` i UNITED STATES liA'liEl-hl'l" OFFICE.

NONSCALDING WATER HEATER. j

Application mcdjuly 30, 1323. Serial No. 654,585.

My invention relates to heat interchaiiglong before the heat-transferring medium as ing appliances in `which the exchange .of heat a whole approaches the boiling point of the i effected through an intermediary and nor said vaporizing liquid, provides, a two-liquid mally liquid medium, and particularly to apmedium for this purpose in which the vapora pliances designed'for heating liquids. izing liquid desirably is not misc'ible wit Viewed in some of its many aspects, my the secondary liquid butis of such higher invention provides a heat-interchanging apspec'iiic gravity as to cause the said secondpliancc of this general class which will auary liquid to float on the vaporizing liquid,

tomat'ically'limit the degree to which heat and provides for the ready use of an easily (55.` y

is transmitted to the heat-receiving member obtainedand vaporizing liquid of highly deof the appliance; which will accomplish this sirable characteristics 1in combination. with Y limitation primarily by converting an int-,erwater as a heat-transferring medium for inediary and normally liquid heat-transmit-- a non-scalding water heater.

. ting medium into a vapor to such an ex- Still further and also mOIe detailed Ob- 70 tent as to reduce the heat transmission jects of -my invention will appear from the through this medium; which will aioi'd a following specification and from the acready storage for liquid forced out ofthe companying drawings, in which heat-interchanging portion oi the appliance Fig. 1 '1S an elevatlOn of a non-Scaldng by the generation of such vapor ;-wh ich will water heater embodying my invention, with 75l 2o automatically return such expelled liquid to a portlon of the container Wall broken away the main portlon 0f the appliancgwhen the t0 SllOW the liSpOSlfilOIl Of the Steam and. excessive heating ceases; whichwill avoid Water ducts Within the same..

any material loss of the vaporizable liquid Fig. 2 is a simplified diagrammatic view medium;` and which will be effective f or showing the disposition of the liquids in a 80 limitingthe temperature, of the heat-receivtemperature-limitin hot water heater when ino' portion of the appliance to a tempera- .theapparatus is co d. O Y

. ture close to thatatwh'ich the intermediary F1g. is a similar diagram showing the or heat-transmitting liquid readily vapordlSpOSitlOn 0 the liquids when the. appaizes- 4 ratus is having its temperature limiting 85 Furthermore, mv invention provides for effect.

the use of an auxiliary heat-carrying liquid Referring first to the diagram of Fig. 2, 'in conjunction with a more readily vaporizthlS ShOWS COIIGSIIBI l having a Water Supable liquid upon whose vaporizing temper- Ply duct 2 @Xtendllg upwardly thIOllgh the ature the control o the heat interchange de- $211119 and SISO having Steam Supply duct 90 pends, and yprovides an apparatus which will disposed within it. This steam supply duct readily permit a relatively expensive vapor- ACOIlflPISS an inlet 58.05.1011 '3 Which entelS ,izable liquid to be used in conjunction with the @Ontaner at a distance above the boti a much larger quantity of a cheap secondary tom of the latter and which Athen extendsliquid; provides means whereby the heat is downwardly and opens through a vT con- 95 40 supplied to the said vaporizable liquid more vIleCtlOrl 14 intO a Vertical Steam pipe 4 which speedily and to a greater extent than to the has its main portion extending upwardly to secondary liquid; provides means whereby a point somewhat below the top O the 0011-. the pressure due to a Avaporizatcui of the tainei and then continued by a downwardly vmore easily vaporizable liquid will primarily extending section 5' of greater surface. Both 100 expel part of the secondary liquid; and prothe said section 5 and the lower portion of A vides an apparatus in which the heating of the riser pipe 4 are connected outside oi. the

the secondary liquid` will coo rate with the container to a return pipe 6 through which more intense heating of `t e .vaporizable -any condensate from the steam is discharged. liquid in aording a speedy interchange of The lower portion of the container is 105 -heat between the heat-supplying and the illed'to a height approximating that of the heatsreceiving portions of the apparatus and inlet portieri ofthe steampipe 3 by la heavy in effecting a sensitive control of the temliquid 7 which is readily vaporizahler at. a -perature of the said heat-receiving portion: temperature belowv that to which the water v My invention also provides a heat-transis to be heated; For 'this'purpo'se I desir- 11o ferring', medium consistinlg of a plurality ofably employ carbon' tetrachloride which, al-

' .liquids one of which wi readily vaporize though it only boils at a temperature of approxiinately 170 F. will vaporize rapidly tained in the'water supply piperemains beat 'a temperature of about 120. Floating low the temperature lto which the heat-transon this vaporizingliquid is a relatively fel-ring liquids are warmed, so that the temgreater volume of water 8 which extends perature ofthe liquid in the heat-receiving substantially to the top of a container. duct is automatically limited. By varying When steam is admitted through the inlet the height of the storage tank with respect pipe 3, the inlet section of this pipe, being to the container, (as shown for example in immersed in the carbon tetrachloride, heats dotted lines in Fig. l) and hence altering the latter intensely and almost instantly the pressure of the liquid in the pipe 10, I v causes it to boil, thereby producing vapor can var the pressure against which vapor which rises into the water above it,`where expels liquid into the storage tank and hence it is condensed (if the water 8 is cold) and can adjust the limiting action of my appara.- again falls to the bottom. Initially, the suptus to some extent so as to. adapt the same plied steam may all be condensed in the to temperature not corresponding exactly to downwardly extending inlet section, but the vaporizing-ppint of the more vaporizlater the steam not condensed in that section able liquid. v passes up the riser 4 and the main section In practice, I may not depend entirely 5 of the steam pipe and also heats both the on this automatic regulating feature of my carbon tetrachloride and the water, so that apparatus, but may also employ an autoboth liquids then act as a medium for c011- matically operating steam control valve so veying heat to the heat-receiving water duct as to reduce the blowing of the liquid into 2. l Any steam condensed in the steam pipe the storage tank where some of it will gradusections iows downward into the return'pipe ally be evaporated and wasted. For ex- 6, Athe customary steam traps in the pipe ample, Fi 1 shows the steam inlet pipev 3 system being omitted in the diagrams yto as control ed by a valve 1l operated lfrom 90 simplify the latter. athermostat 12 disposed in the upper porlVhenthe water 8 in the container reaches tion of the container l, the steam inlet pipe a temperature of about 120, this water no entering the container somewhat above the longer condenses the vapor of the carbon top of the carbon tetrachloride 7 and the tetrachloride but rather tends to superheat connection of the discharge pipe 10 to the 95 the vapor 'and hastens the vaporizing, so that container. The inlet pipe 3 is connected this vapor accumulates rapidly in the top atiitsv lower end through a T 14 to a steam c of the container or `above the top of the riser pipe 4 which is connected at its upper water 8, where it creates a pressure above the vend to the top of a'. coiled steam pipe section wat/er. To utilize this pressure, I provide 5, and the lower end of this coil is con- 100 a' storage tank 9 disposed above the normal nected through an outlet pipe 15 and a steam level of the water and having its bottom trap 16 to a suitable drain pipe. Likewise, connected to the cntainer by a pipe 10 the T 14 is connected through a drain pipe e which desirably leads vinto the container at 17 and a trap 18 to a; drain pipe.

a point abovel the normal level of the carbon The water which is to be heated enters the tetrachloride. This storage tank has at its container through the inlet pipe 19 andl then top an air vent 10 but is empty when the passes through pipes 20 extending vertically apparatus is cold. soon as pressure is through the container proper, which conproduced above the waer by the accumulatainer forms the central section for a water tion of vapor from .the volatile liquid, this tank having an upper outlet 21 for the 110 pressure forces'water up the pipe 10 and heated'water. 4To store the waterfor'ced out into thestorage tank 9, thereby gradually *through the-discharge pipe 10 by the presstoring-water in this tank as shown in Fig.' sure of the vapor, I connect this pipe 10 to 3 and correspondingly 'lowering the level of the bottom of a storage tank 9 having an air e the water in the container as shown in the vent 22 similar to that mentioned inecon-- 115 same figure. v c.

As long as both the heat-supplying duct When a thermostatic valve 11 is thus e`m- (here comprising-steam pipe portions 3,V 4 ployed and isin proper operative condition, and 5), and the Aheat-recei'v ng duct (name-V this valve will control the supply of, steam ly the water pipe 2) are immersed in the automatically Vso as-to maintain approxi heat transferring medium consisting of the mately the desired temperature in the heated two, liquids, ythese liquids ail'ord a ready conwater without requiring my safety feature duction of heat from one to the'other. Howto operate. However, if this valve should ever, asthe level of the upper liquid falls, fail to operate, theformation of vapor portions of bothn of these-ducts are ex'posed causes liquid to be forced into the storage to an `increasing extent above the same and tank 9 whereupon the reduction in the heat since any vapor is a much poorer conductortransfer due t0 the formation of this vapor of heat than aliquid, the rate of the heatautomatically limits the temperature of the transferring is considerably decreased. Conwater, thereby acting as a positive safeguard u sequently, the effective temperature atfor limiting the temperaturey to. which the 130 lwater isy heated. In practice i myl two-liquid arran in the tank remains I idesirably provide -a gage glass 23 from w ich the-level of the liqu1ds can be seenat a glance, and IA j have found that if the thermostatic valve 1s blocked'wide open while no water is being withdrawn from the outlet 21 of the tank, the level of the upper liquid 4falls rapidly while the temperature of the heated water practically constant. Hence my simple arrangement affords an entirelyautomatic control and b selecting al vapori'zable liquid of a suita le rapidvapori-zing` temperature, I can readily secure the desired temperaturev limitation in the heat-receiving liquid. Where the latter is water, as employed in hospitals, asylums 'or the like for administering baths, carbon tetrachloride is highly suitable as a Vaporizable liquid, since it permits .a relatively large v'quantity of water to iloat on it and readily limits 4the temperature of the heated water to about 120;F,

Since the vapor occupies a much greater s ace than the unvaporized liquid, a relatively small quantity ofthe carbon tetrachloride is ample for the purpose, but I desirably employ a lsomewhat greater quantity yso as to have more of the hot Steam pipe section immersed in it, as for example about one part ofcarbon tetrachloride to 25 parts Vby volume of water. In practice, a little of the vaporized carbon tetrachloride i may' be expelled with the water into the storage tank, but as the latter .is cooled by the outerair. and only has asmall air vent, l anyvapor' forced into itis readily condensedV and iiows backinto the container. Hence the use'of a relative y small quantity of the vaporizable liquid but also prevents any substantial waste of the same. Further-more,

` since-the-temperature limiting feature of my apparatus involves no lmoving mechanism, it requiresno attention of any-kind and has nothing about it to get ou of order.

By using non-miscible liquids in the above manner, I can limit the expulsion ofliquid into 'the tank; almost wholly .to the lighter liquid, thereby reducing even the gradual A, evaporation within the tank Voi the heavier li uid which, as in the case vof carbon tetrach oride is 'much more expensive, and I can also' secure greater sensitiveness liquids which'are miscible. However, I may employ two miscibleliquids of different vaporizing points'v and hence do not wish Fto be limited in this respect. Neither-do I wish to'l be limited to using liquids one o which readilyv vaporizes at s bstantiall'y the desired limiting'temperature, as theeiective limiting temperature attained -with my in- 'Vention can be varied by raising or lowering the storage'tank so asto decrease or increase the readiness with which the generated vapor forces liquid into the tank.

' rangement ment not only permits 'within the container,

than with so also, while I have described my inval-' tion as employed for water ,heating purposes, I do not wish to be limited to this use .of the same nor-to the use ofthevaporizable liquid which I have found part-icularly advantageous in hydrotherapeutie installa- ;tions. Neither do I wish to be limited to the above described construction andarof a suitable heat-transferring apparatus, itbeing `obvious that the same might` be varied in many wa-ys Without de partng either from the spirit of my invention or from the appended claims. 1

I claim as my invention 1. A heat interchange appliance comprising a' lclosed container, a Aheat supplying duct and a heat receiving duct both extending through the container; a heat transferring medium withi the container comprisin two non-miscible liquids of dierent speci c gravities and vaporizing points, anda storage tank )connected to the container within the zone of the-lessvolatile liquid.

2.*A heat interchange appliance compris- Aing a closed container, a heat supplying duct and a heat receiving duct both extending .through the container; a heat transferring medium within the container comprising two non-'miscible liquids of different spe-l cific gravities and vaporizing points, a stor-4 age tank disposed higher than the normal top of the said medium, and a connection leading from thebottom of the tank to the' v container and connected to the latter w-ithin the zone Vof the less volatile liquid, the storage tank having a air. 3. A heat interchange appliance for heating a Huid to asubstantially predetermined vent open tothe outer` limiting temperature only, `comprising a .1

closed container, a heat supplying duct disposed' within the container and connected to a supply of heating fluid at a tempera- `ture in excess of the said limiting temperature, alheat receiving duct connected to the :'lnid which is to be heated and also disposed aA heat transferring medium within the containerl comprising y two non-miscible liquids of diderent -specific gravities -and vaporizing points, the quantity *of* the vliq vaporizing point belnggsuch that its vapor will more than fill the container, the two liquids together being'of such a volume 'as normally ltoiill at least the 4greater part of the container, an expansion tank disposed 4 higher than the container, and a duct con-V necting ,the bottom of the tank with the containerat a point lnormallyaopposite the liquid having the higher vaporizing point.

4. In a' heat interchange a plianc'e, aclosed container, la heat trans erring medium partly filling the container and comprising a --relatively heavy liquid and la lighter liquid normally iioating on the said A iso ui'd having the lower;

heavy liquid, the heavier liquid having a lower vaporizing point than the lighter iquid, a heat transmitting' duct extending through both liquids and through the space above the lighter liquid, ay heat transmitting duct extending initially into the heavier liquid and thereafter into the lighter liquid, and a ventedv tank connected to the container abo-ve vthe heavier liquid and below the normal level of the lighter liquid.

5. A heat interchange appliance coinprising a closed container, a heatl supplying duct and a heat receiving duct both disposed within the container-j and a liquid mixture within the container comprising a layer of a liquid heavier than water and of lower vaporizing temperature than water, and a larger amount of water normally floating upon the said layer, the heat sup-l plying duct having a downwardly directed entrance yportion disposed below the normal top of the heavier liquid, and a continuation portion connected to the bottom of the said entrance portion and extending through both liquids into the space above them, and a trap connected 'to the connec-l tion between the said two duct portions.

6. A non-scalding hot water heater comprising a closed container, a steam pipe and container, a liquid heat-transferring medium partly filling the container and comprising water andy a second liquid notfmiscible with water and of distinctly different specific gravity and lower boiling point than water, and a vent duct connected tothe container within the zone of the water and ex.-

tending upwardly from its said connection.

A water heater as per -claim 6, inl

which the steam pipe has its hottest portion disposed in the said second liquid and in which a relatively cooler portion of the steam pipe as well as a part of the water pipe .extend into the space above the said medium.

8. A water heater as per claim 6, in which the normal quantityv of water is considerv ably greater than that of the said second liquid.

9. A non-scalding hot water heater comprising a closed container, a steam duct` and a water duct both extending throughthe container, anda liquid'medium partlylilling the container," the said medium comprising carbon tetrachloride and water,

both the steam pipe and the water pipe havtion.

a water pipe both extending -through the ing portions disposed above the level of the liquld medium .when the heater is in operation, and a vent duct connected to the container within the -zone of the water and extending upwardly from its said connec- 10. A non-scalding hot water heater comprising a closed container, a liquid medium partly filling the container, the said mediuln comprising'carbon tetrachloride and a relatively greater quantity' of water, a steam duct and a water duct extending through the container and through both of the said liquids; a vented and normally empty storage tank; and a pipe leading from mtic gravity andrelatively higher vaporiz'ing vpoint;a heat-transmitting duct and a heatreceiving duct both extending through the container and `through both liquids and having portions of both ducts disposed in the space between the top of the container and the top of the lighter liquid; and a venting duct connected to the container Within the zone of the lighter liquid and near the normal top of the heavier liquid and extending upwardly from its said yconnection.

12. A'non-scalding hot water heater comprising a closed container, a layer of carbon tetrachloride the container, a relatively larger volumeof water floating thereon and having its normal top spaced from the top of the container; aheating duct and a water duct both extending through both of the said liquids and into the space above the water, the heating duct being disposed for vheating the carbon tetrachloride more intensely than the water; and a venting duct connected to the container Awithin the zone of the water and normally slightly above the top of the carbon tetrachloride.

Signed at Chicago, Illinois, July 27th, 923.

FRED J," PosTEL. 

